My dog has multiple tumors. What symptoms mean I need a vet?

Awww, he's a handsome guy! Tumors which appear as lumps and bumps on the skin or can be felt or seen but are just under the skin are common with age; some are benign and not problematic, while some can be life threatening. Lipomas are common, which are usually relatively soft, freely movable under the skin (you can push it around) and are non painful. Generally these are slow growing, they do not cause cancer elsewhere in the body (though its very common for a dog to have multiple lipoma tumors) and rarely cause a problem. Mast cell tumors, on the other hand, can be aggressive and can cause systemic illness. They can look like lipomas; the only way to know the difference is for your vet to perform a fine needle aspirate (where they will poke the bumps with a needle to get a sample of the cells and then look at them under a microscope. Other skin tumors can include squamous cell carcinomas which can be very locally invasive and aggressive, and grow quickly.
Keep an eye on the lumps and bumps. If any of them are quickly growing, start to break open or bleed, or any of them are painful when touched, he should be seen by a vet. A golfball sized tumor is immensely easier to remove than a football sized one--so addressing a lump when its small is much better Grady and also will cost less than waiting until its very large.
I hope that helps you, thank you for asking Petco Pet Education Center, formerly Petcoach!